Turbine assembly for a torque converter including a tab plate and turbine shell brazed together and method of forming

ABSTRACT

A turbine assembly is provided. The turbine assembly includes a turbine shell and a tab plate connected to the turbine shell, the turbine shell and the tab plate being brazed together. A method of forming a turbine assembly impeller is also provided. The method includes aligning a tab plate with a turbine shell with a braze material therebetween and brazing the tab plate and turbine shell together by melting the braze material.

This claims the benefit to U.S. Provisional Patent Application No.61/813,078, filed on Apr. 17, 2013, which is hereby incorporated byreference herein.

The present disclosure relates generally to turbine assemblies fortorque converters and more specifically to a connection of a tab plateto a turbine shell of a turbine assembly.

BACKGROUND

U.S. Pat. No. 8,257,042 discloses a power transmitting member fastenedto a turbine shell by a rivet.

U.S. Pat. No. 4,646,886 discloses a torque transmission member mountedon a turbine.

U.S. Publication No. 2007/0253823 discloses a spring retainer fixed to aturbine shell by folded blade tabs.

SUMMARY OF THE INVENTION

A turbine assembly is provided. The turbine assembly includes a turbineshell and a tab plate connected to the turbine shell, the turbine shelland the tab plate being brazed together.

Embodiments of the turbine assembly may also include one or more of thefollowing advantageous features:

The turbine assembly may include elastic dampers and the tab plate maybe arranged for driving the elastic dampers. The elastic dampers may bearc springs and the turbine assembly may include a retainer supportingthe elastic dampers. The turbine shell and tab plate may be brazedtogether by a braze material, which extends between an outer surface ofthe turbine shell and an inner surface of the tab plate. The turbineshell may include at least one hole passing therethrough, the brazematerial surrounding the hole. The turbine assembly may include aturbine core ring, the at least one hole being radially outside of theturbine core ring.

A method of forming a turbine assembly impeller is also provided. Themethod includes aligning a tab plate with a turbine shell with a brazematerial therebetween and brazing the tab plate and turbine shelltogether by melting the braze material.

Embodiments of the method may also include one or more of the followingadvantageous features:

The turbine shell may include a hole extending between an inner surfaceand an outer surface thereof and the brazing may include applying thebraze material into the hole. The brazing may further include heatingthe braze material such that a capillary action pulls the braze materialaway from the hole and in between an inner surface of the tab plate andthe outer surface of the turbine shell. The capillary actions causes thebraze material to flow radially outward with respect to an axis of thehole. The method may further include arranging tabs of the tab platecircumferentially between elastic dampers. The method may furtherinclude brazing the turbine shell and turbine blades together as the tabplate and the turbine shell are brazed together.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described below by reference to the followingdrawings, in which:

FIG. 1 shows a cross sectional view of a turbine assembly according toan embodiment of the present invention;

FIG. 2 shows a view of a section of the turbine assembly along A-A ofFIG. 1;

FIGS. 3 a to 3 c show a preferred embodiment of a method of forming theturbine assembly; and

FIG. 4 shows a torque converter including the turbine assembly.

DETAILED DESCRIPTION

FIG. 1 shows a cross sectional view of a turbine assembly 10 accordingto an embodiment of the present invention and FIG. 2 shows a view of asection of turbine assembly 10 along A-A of FIG. 1. Turbine assembly 10includes a tab plate 12 brazed to a turbine shell 14. Tab plate 12includes a base portion 16 extending along an outer surface 18 ofturbine shell 14 and a tab portion 20 protruding away from base portion16. In the cross sectional view show in FIG. 1, base portion 16 and tabportion 20 together have approximately an L-shape. At a rounded portion19 of turbine shell 14, outer surface 18 of turbine shell 14 has arounded shape and an inner surface 22 of base portion 16 is contoured tothe shape of outer surface 18. An inner surface 24 of turbine shell 14supports a plurality of turbine blades 26, which extend between innersurface 24 and a turbine core ring 28. Outer surface 18 of turbine shell14 faces away from core ring 28. Radially inside of rounded portion 19of turbine shell 14, turbine shell 14 includes a flat connecting portion30, connectable to a turbine hub by a rivets passing through holes 36 inconnecting portion 30. Turbine assembly is centered about an axis 38.Unless otherwise specified, the use of the terms radially, axially andcircumferentially herein will be with respect to axis 38.

In this embodiment, tab plate 12 is used for circumferentially drivingelastic dampers 40, which in this embodiment are arc spring 42 supportedby a spring retainer 44 to form a damper assembly 32. Damper assembly 32may be coupled to a clutch of the torque converter.

Rounded portion 19 of turbine shell 14 includes a brazing hole 46passing through turbine shell 14 from outer surface 18 to inner surface24. In this embodiment, brazing hole 46 is formed in turbine shell 14radially outside of core ring 28. Brazing hole 46 is formed between twoturbine blades 26, which may be connected to turbine shell 14 before orafter turbine shell 14 and tab plate 12 are brazed together. Blades 26may be connected to turbine shell 14 via blade tabs 48 that are insertedin slots passing through turbine shell 14 and bent to engage outersurface 18. Similarly, blades 26 may be connected to core ring 28 in thesame manner, by engaging blade tabs 50 in slots 52 in core ring 28 andbending blade tabs 50. In a preferred embodiment, after blades 26 areconnected to turbine shell 14 and core ring 18 by respective tabs 48,50, blades 26 are brazed to both turbine shell 14 and core ring 18. Thebrazing may be accomplished as described in U.S. Pat. No. 7,918,645.

In a preferred embodiment of the method of the present invention, whichis shown schematically in FIGS. 3 a to 3 c, tab plate 12 is placed downon a support surface and turbine shell 14 is placed on top of tab plate12. Tab plate 12 may be formed as a single ring-shaped integral piecewith a plurality of axially extending tabs 54 protruding downward awayfrom turbine shell 14. In this embodiment, tabs 54 are circumferentiallyspaced apart from each other by gaps 56 for receiving elastic dampers40, i.e., arc springs 42. After turbine shell 14 is placed on top of tabplate 12 and appropriately aligned such that brazing holes 46 are allcentered around a center axis of tab plate 12 and outer surface 18 ofturbine shell 14 is in close contact with inner surface 22 of tab plate12, a braze material 62 is placed in each of brazing holes 46. Then,braze material 62 is heated such that braze material 62 is liquefied anda capillary action pulls the braze material 62 radially away from eachrespective hole 46, with respect to an axis of the respective hole 46,in between inner surface 22 of the tab plate 12 and outer surface 18 ofturbine shell 14. Braze material 62 is then cooled to permanentlyconnect tab plate 12 and turbine shell 14.

In a preferred embodiment of the present invention, turbine shell 14 andcore ring 28 are connected together by tabs 48, 50 of blades 26 beforetab plate 12 and turbine shell 14 are brazed together. This allowsblades 26 to be brazed to turbine shell 14 and core ring 28 at the sametime that turbine shell 14 and tab plate 12 are brazed together. Forexample, braze material 62 may be placed in holes 46 and into brazinglocations between blades 26 and core ring 28 and brazing locationsbetween blades 26 and turbine shell 14. Then, tab plate 12, turbineshell 14, blades 26 and core ring 28 may be passed through a brazingfurnace together to melt the braze material 62, which permanentlyconnects tab plate 12, turbine shell 14, blades 26 and core ring 28together at the same time after the braze material 62 is cooled.

In an alternative embodiment, instead of tab plate 12 being formed as asingle integral ring-shaped piece, tab plate 12 may be formed as aplurality of separate tab plates spaced circumferentially from eachother on turbine shell 14. For example, each separate tab plate mayinclude a tab 54 and may be individually brazed to turbine shell 14 bybraze material 62. In such embodiments, it may be helpful to firstfasten each separate tab plate to turbine shell 14 before brazing. Forexample, each separate tab plate may include a tab similar to tab 50 ofblade 26 and may be inserted into slots in turbine shell 14 similar toslots 52 in core ring 28 to fasten the individual pieces to turbineshell 14. Other fasteners may also be used in other embodiments, such ashooks for example.

After turbine shell 14 and tab plate 12 are brazed together, tab plate12 may be engaged with a driven component, which in this embodiment isdamper assembly 32. Tab plate 12 and spring retainer 44, which retainsarc springs 42, may be meshed together, by aligning tabs 54 of tab plate12 between springs 42 of spring retainer 44 as shown in FIG. 3 c. Arcsprings 42 may be positioned in gaps 56 between tabs 54. Turbineassembly 10 may be then used in a torque converter of a motor vehicle,which transfers power from a crankshaft of an engine to a transmission.

A schematic of a torque converter 110 including turbine assembly 10 isshown in FIG. 4. Tab plate 12 brazed to turbine shell 14 is arranged forcircumferentially driving damper assembly 32 by extending intocircumferential gaps between dampers 40. Spring retainer 44 may becoupled to a clutch plate 114 which includes a friction surface 112 forengaging a cover 116 of torque converter 110, which connects to anengine crankshaft. Torque converter 110 also includes an impeller orpump 118 opposite turbine assembly 10. In other embodiments, turbineassembly 10 may be used in a torque converter in other arrangements andtab plate 12 may be used to drive a component other than damper assembly32.

In an alternative embodiment, instead of turbine shell 14 includingbrazing holes 46, brazing holes may be included in tab plate 12. Brazematerial 62 may then be melted into the brazing holes in tab plate 12 topermanently connect tab plate 12 to turbine shell 14. In this case, thepart may be brazed with the tab plate resting on top of the shell.

In the preceding specification, the invention has been described withreference to specific exemplary embodiments and examples thereof. Itwill, however, be evident that various modifications and changes may bemade thereto without departing from the broader spirit and scope ofinvention as set forth in the claims that follow. The specification anddrawings are accordingly to be regarded in an illustrative manner ratherthan a restrictive sense.

What is claimed is:
 1. A turbine assembly comprising: a turbine shell;and a tab plate connected to the turbine shell, the turbine shell andthe tab plate being brazed together.
 2. The turbine assembly as recitedin claim 1 further comprising elastic dampers, the tab plate arrangedfor driving the elastic dampers.
 3. The turbine assembly as recited inclaim 2 wherein the elastic dampers are arc springs.
 4. The turbineassembly as recited in claim 2 further comprising a retainer supportingthe elastic dampers.
 5. The turbine assembly as recited in claim 1wherein the turbine shell and tab plate are brazed together by a brazematerial, the braze material extending between an outer surface of theturbine shell and an inner surface of the tab plate.
 6. The turbineassembly as recited in claim 5 wherein the turbine shell includes atleast one hole passing therethrough, the braze material surrounding thehole.
 7. The turbine assembly as recited in claim 6 further comprising aturbine core ring, the at least one hole being radially outside of theturbine core ring.
 8. The turbine assembly as recited in claim 1 furthercomprising a driven component, the tab plate arranged forcircumferentially driving the driven component.
 9. A torque convertercomprising the turbine assembly as recited in claim
 1. 10. A method offorming a turbine assembly impeller comprising: aligning a tab platewith a turbine shell with a braze material therebetween; and brazing thetab plate and the turbine shell together by melting the braze material.11. The method as recited in claim 10 wherein the turbine shell includesa hole extending between an inner surface and an outer surface thereof,the brazing including applying the braze material into the hole.
 12. Themethod as recited in claim 11 wherein the brazing further includesheating the braze material such that a capillary action pulls the brazematerial away from the hole and in between an inner surface of the tabplate and the outer surface of the turbine shell.
 13. The method asrecited in claim 12 wherein the capillary actions causes the brazematerial to flow radially outward with respect to an axis of the hole.14. The method as recited in claim 10 further comprising arranging tabsof the tab plate circumferentially between elastic dampers.
 15. Themethod as recited in claim 14 wherein the elastic dampers are arcsprings.
 16. The method as recited in claim 15 wherein the arc springare supported by a spring retainer.
 17. The method as recited in claim10 further comprising brazing the turbine shell and turbine bladestogether as the tab plate and the turbine shell are brazed together.